Study finds possible link between blood type and COVID-19 risk

Researchers at Emory and Harvard find attraction to blood group A antigen

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Do you know your blood type? If not, you might want to find out, because a new study has found evidence that certain blood types could be associated with a greater risk of contracting COVID-19.

Researchers at Emory University School of Medicine and Harvard Medical School assessed a protein on the surface of the SARS-CoV-2 virus (the cause of COVID-19) called the receptor binding domain, or RBD. The RBD is the part of the virus that attaches to the host cells, so it is an important research target for understanding how infection occurs. The study was published Wednesday in the journal Blood Advances.

The scientists assessed synthetic blood group antigens on respiratory and red blood cells found in people with blood types A, B, and O, and analyzed how the SARS-CoV-2 RBD interacted with each. They found the RBD had a strong preference for binding to blood group A found on respiratory cells. The RBD showed no preference for group A red blood cells, however, or any of the other respiratory or red cells.

“It is interesting that the viral RBD only really prefers the type of blood group A antigens that are on respiratory cells, which are presumably how the virus is entering most patients and infecting them,” said study author Sean R. Stowell of Brigham and Women’s Hospital at Harvard Medical School. “Blood type is a challenge because it is inherited and not something we can change. But if we can better understand how the virus interacts with blood groups in people, we may be able to find new medicines or methods of prevention.”

Stowell said the team’s findings alone can’t fully describe or predict how coronaviruses like SARS-CoV-2 would affect patients of various blood types.

“Our observation is not the only mechanism responsible for what we are seeing clinically, but it could explain some of the influence of blood type on COVID-19 infection,” he said.

While further research is needed to understand that influence, the paper adds to findings from earlier Blood Advances studies suggesting a possible link between blood type and COVID-19 susceptibility and severity, the team wrote in a press release.

The Emory researchers who worked on this study — Drs. Connie M. Arthur, Jianmei Wang, Hans Verkerke, Cassandra D. Josephson, Daniel Kalman and John D. Roback — are part of the Center for Transfusion Medicine and Cellular Therapies at the medical school.

A study by Yale researchers has found that a series of biomarkers, or biological signals, associated with white blood cell activation and obesity can indicate severe outcomes in COVID-19 patients. The study was published Friday in the journal Blood Advances.

“Patients with high levels of these markers were much more likely to require care in the intensive care unit, require ventilation, or die due to their COVID-19,” said lead author Dr. Hyung Chun, an associate professor of medicine in cardiovascular medicine and pathology and director of translational research at the Yale Pulmonary Vascular Disease Program.